Actually increasing it to 4 per pop will not make much difference, except in the very early PreHistory game.
4 means 1 more per pop needed so in Ancient when food is abundant a 20 city would need all of 20 more food per turn?
No, it would not, because it had probably lost more than that from food decay anyway so those 20 extra would only reduce the decay, and still grow just as fast.
Only once the threshold of reducing decay and increase of food due to total population is reached will it start turning downwards in a noticeable fashion really, and only until reaching Vertical Farming after which it will sky-rocket again.
If you do not trust my non-existent proof just try setting it to 5 in an ongoing Classical game and see if there is much noticeable difference.
Cheers
4 means 1 more per pop needed so in Ancient when food is abundant a 20 city would need all of 20 more food per turn?
No, it would not, because it had probably lost more than that from food decay anyway so those 20 extra would only reduce the decay, and still grow just as fast.
Only once the threshold of reducing decay and increase of food due to total population is reached will it start turning downwards in a noticeable fashion really, and only until reaching Vertical Farming after which it will sky-rocket again.
If you do not trust my non-existent proof just try setting it to 5 in an ongoing Classical game and see if there is much noticeable difference.
Cheers